The top part of the ass that flops out of fat peoples pants when they get up from previously sitting down.
Dude your friend Zach has some serious ass flop going down.
by KrypticDeath July 14, 2010
1 more definition
Some one who has no ass. When you look at there ass there is nothing there .
Damn look at her (girl walks past) yeah her face is nice but she an assflop
by Nolife56 May 06, 2013